Scaffolding creates platforms that provide a stable and safe structure for working at elevated heights. A scaffold structure includes horizontal members and vertical members that are assembled into a framework. At the desired height, scaffold boards are attached to scaffold structures to create a working platform or working surface. The scaffold boards can be wooden or metal boards that are supported on the structure by horizontal scaffold members. One scaffold system which allows for flexibility in the horizontal position of a scaffold platform is shown in U.S. Pat. Nos. 5,078,532 and 5,028,164, both to Williams (incorporated herein by reference). The Williams patents show vertical scaffold members with cups placed thereon with latchable horizontal members where the latches interlock the cups on the vertical members. This system, and other, allow for great flexibility in assembly of the scaffold structure and placement of the working surface. Generally, the scaffold structure extends above the deck surface to provide a safety rail system for workers on the deck.
A common problem with scaffolding is providing a safe means to access the elevated platform. Generally, a worker either climbs the assembled scaffold structure or a ladder is placed on the outside of the platform structure. In either case, the worker uses the exterior of the scaffold structure to access the scaffold working surface with attendant risks. One such scaffold ladder is shown in U.S. Pat. No. 6,415,891 to the applicant (incorporated herein by reference). As the scaffold structure generally extends above the platform working surface, workers either have to climb over the safety rails to access the working surface or the safety rails have to have a gap in the rail system to allow a worker to pass through the safety rail system. One such system employing an external ladder and a gap in the safety rail system is shown in U.S. patent application Ser. No. 09/767,569 to the applicant. Any exterior ladder, however, presents a risk to the climber—there are no intermediary levels to act as a stop in case of a fall. Other systems have been devised for accessing scaffold decks, including such as scaffold stairs, as shown in U.S. Pat. No. 6,044,930 to the applicant. Scaffold stairs can be cumbersome and heavy and, for a short term scaffold structure, may be more than needed.
Attempts have been made to safely accommodate a ladder in the interior of a scaffold structure. One such method being the placement of a framed opening on a scaffold platform to which a scaffold hatch is placed to allow the opening to be closed. One such scaffold hatch is shown in U.S. Pat. No. 5,746,289 to Williams (incorporated herein by reference). The scaffold hatch, however, is cumbersome and is not designed to support safety rails around the opening.